which groups of neurons are activated in a model when it processes an image
They are NOT neurons in any biological sense. Can we have a proper name for this and stop pretending it's like how a brain works and stop using misleading terms like Learning (it's storage of curated data) and AI (It's artificial, but not intelligent or stupid).
For a brief moment I wondered was it some sort of a scanner examining actual brains.
Though the tool sounds interesting.